Oliver, https://bugs.launchpad.net/bugs/1863939 is filled against valid kernel. What exactly is wrong with this bugreport? Yes, sdm850-based laptops is supposed to boot with generic arm64 kernel, as most of the necessary code was upstreamed by the time 5.4 was released. And, yes, generic 5.4 kernel from mainline PPA does boot on this laptop.
Why so? Isn’t kernel build config issue have to be communicated with Canonical one way or another?
Also, please notice that I mentioned mainline PPA in second bugreport only because of first issue. You know, I can not fill bugreport about not working keyboard if kernel from Ubuntu repository doesn’t even boot.